Apparatus for finishing metal parts



Sept. 15, 1964 T. a. GARVEY 3,148,435

APPARATUS FOR FINISHING METAL PARTS Filed April 12. 1961 2 Sheets-Sheet 1 FIG.2.

INVENTOR. THOMAS G. GARV EY ATTORNEY Sept. 15, 1964 T. G. GARVEY APPARATUS FOR FINISHING METAL PARTS Filed April 12, 1961 2 Sheets-Sheet 2 FIG. 5.

FIG. 6.

INVENTOR.

THOMAS G. GARVEY ATTORNEYS United States Patent 3,148,485 APPARATUS FOR FINISHING METAL PARTS Thomas G. Garvey, Blue Anchor, NJ. Filed Apr. 12, 1961, Ser. No. 102,584 1 Claim. (ill. 51-164) This invention relates to an apparatus for finishing metal parts and in particular large thin sheet metal parts prior to bending or forming.

In the use of conventional barrel finishing equipment it has been found that large sheet metal parts of approximately inch thickness or less, such as employed for chassis or panels, cannot be satisfactorily finished. In accordance with the barrel finishing process heretofore employed the metal part floats in an abrasive finishing media Within the barrel and consequently the part often turns at an angle to the flow of the abrasive finishing media during the tumbling cycle. Due to the different rates at which the layers of the media move, large thin sheet metal parts in particular are subjected to bending forces which effect distortion of the sheet metal. Attempts have been made to overcome this problem by means of a fixture type finishing barrel in which the parts to be finished are clamped in position transversely of the barrel. While this positively precludes bending of the sheet metal, the clamping of the metal part in fixed relation to the barrel gives rise to another deleterious effect, namely peening of the sheet metal edges.

It is an object of this invention to provide a finishing barrel capable of finishing large thin metal parts without bending or peening.

Further objects are to provide a finishing barrel having a plurality of transverse partitions which may be readily inserted and removed to form multiple compartments of predetermined size; to provide a finishing barrel of hexagonal shape in cross section, two sides of which are open for insertion and removal of the partitions, abrasive media and metal parts to be finished; to provide a finishing barrel of the character described having a solid cover and 'a drain and dumping cover selectively fitted over the open sides of the barrel, and to provide a drain and dumping cover comprising two perforated members each covering one open side of the barrel, the members being hingedly connected to permit the members to be raised out of engagement with the barrel independently of each other, thereby effecting ready removal of the abrasive media from the barrel without accidental displacement of the parts being finished or the partitions from the barrel during the dumping operation.

Other objects of the invention will be manifest from the following description of the present preferred forms of the invention, taken in connection with the accompanying drawings, wherein:

FIG. 1 is a perspective view of a finishing barrel constructed in accordance with the present invention, the cover thereof being removed to disclose structural details;

FIG. 2 is a perspective view of a solid cover for the finishing barrel of FIG. 1;

FIG. 3 is a perspective view of a drain and dumping cover for the finishing barrel of FIG. 1;

FIG. 4 is a transverse sectional view of the assembled finishing barrel of the present invention, portions thereof being broken away to disclose details of construction;

FIG. 5 is a front elevational view of the finishing barrel of the present invention with the solid cover in place for tumbling, portions thereof being broken away to disclose details;

FIG. 6 is a view similar to FIG. 5 showing the drain and dumping cover in place for use in lieu of the solid cover;

3,148,485 Patented Sept. 15., 1964 FIG. 7 is a transverse sectional view of the finishing barrel of the present invention illustrating the manner of inserting and removing the partitions forming a part thereof;

FIG. 8 is a transverse sectional view of the finishing barrel of the present invention illustrating the manner of dumping the abrasive media from the barrel; and

FIG. 9 is a perspective of a modified form of partition constructed in accordance with the present invention.

Referring now in greater detail to the drawings the finishing barrel of the present invention generally comprises a drum 10 of hexagonal shape two adjacent sides of which are open and adapted to receive a perforated drain and dumping cover 11 or a solid tumbling cover 12.

Hexagonal drum 10 includes spaced hexagonal end plates 13 which are joined by a side unit 14 which is bent into engagement with and secured to four edge members of the end plates. Pintles 15 are centrally secured to the outer faces of end plates 13 for engagement with any suitable supporting and rotating structure. The remaining two adjacent open sides of the drum are provided with a fiat supporting open framework 16 which extends beyond the limits of the drum. Framework 16 is provided with a plurality of peripheral spaced recesses 17 adapted to receive pivoted clamp assemblies 18, each assembly including a threaded shaft 19 pivoted either to end plates 13 or side unit 14. A wing nut 20 is threadedly engaged with shaft 19 of each assembly. The face of framework 16 is lined with sponge rubber, as indicated at 21, to effect a water-tight seal.

Opposite internal faces of drum 10' are rabbeted to form guideways 22 into which hexagonal partitions 23 of substantially the same size and shape as end plates 13 are slid into place in the manner illustrated in FIG. 7. No extraneous means are necessary to hold the partitions in position and they may be readily inserted and removed as desired.

Drain and dumping cover 11 comprises a pair of like, angularly disposed perforated or screen covered rectangular members 24 and 25 hingedly connected at 26. Members 24 and 25 are provided with a plurality of strategically positioned edge recesses 27 adapted to be aligned with recesses 17 of framework 16. Perforated cover 11 permits rinsing and dumping of the barrel after the finishing operation. By hinging members 24 and 25 together, either of the latter can be opened independently of the other to dump the abrasive media and still retain the partitions 23 and metal parts in place within the barrel (see FIG. 8).

Solid tumbling cover 12 includes a lower solid portion 28 of rectangular conformation and corresponding in size to member 24 of drain and dumping cover 11. A plurality of edge recesses 29 are adapted to be aligned with recesses 27 of member 24. The upper terminal or portion 28 issues into an upwardly and rearwardly extend ing like portion 30 corresponding in size and shape to member 25 of cover 11. Edge recesses 31 are adapted to be aligned with edge recess 27 of member 25.

In use of the present invention, partitions 23 are preferably located approximately 2 inches apart and the thin sheet metal parts to be finished indicated at 32 are centrally positioned in compartments 33 formed by partitions 23. A commercially available abrasive finishing media 34 is next added to the barrel. This media is preferably added by first pouring the abrasive stones on each side of the metal sheets until the compartments are at least onehalf full. Then a commercial compound is added to water and the mixture poured into the barrel until it reaches the level of the stones. Optimum results are obtained when there is approximately 1 inch of abrasive media between each face of the sheet metal part and partitions 23.

After the abrasive media has been added, solid tumbling cover 12 is placed in position as illustrated in FIGS. 4 and 5 and clamping assemblies 18 pivoted into operative position and tightened in an obvious manner to urge cover 12 into water-tight relation with sponge rubber seal 21. The barrel is then rotated at a rate of about 15 r.p.m. until the desired finish is obtained.

During the entire tumbling cycle sheet metal parts 32 are free to move with finishing media 34 within the confines of compartments 33, partitions 23 functioning at all times to retain the sheet metal parts in transverse relationship to the barrel.

After the finishing of the sheet metal parts has been effected, the barrel is rotated until solid tumbling cover 12 faces upwardly. Cover 12 is then removed and drain and dumping cover 11 substituted therefor. Upon rotation of the barrel to the approximate position shown in FIG. 6, the liquid portion of the abrasive media may be drained therefrom through the perforations in members 24 and 25. After draining has been effected, the abrasive stones many be removed from the barrel by raising either of members 24 or 25 as shown in FIG. 8. Casual displacement of the metal parts 32 or partitions 23 is prevented by the remaining member 24 or 25 which is clamped to drum 10. To take out parts 32, drain and dumping cover 11 is removed.

The finishing barrel of the present invention is preferably designed so that the width of each compartment 33 is smaller than the width of the part being tumbled. This positively prevents the part turning at right angles to the flow of the abrasive media. Additionally by providing removable partitions the barrel is readily adapted to provide compartments of varying size to meet different needs. For example if sheet metal parts with formed edges such as covers are to be finished, every other partition 23 may be removed to provide a series of 4 inch compartments, thereby affording compartments in which the recommended 1 inch of abrasive media is on each side of the part being tumbled.

In FIG. 9 there is illustrated a modified form of partition designated 35 which is of substantially the same size and shape as partition 23. In accordance with this form of the invention there is provided a series of openings 36 in the partition along the outer limits thereof, these openings being approximately 1 /2 inches in diameter to allow abrasive stones to pass therethrough and thereby efiect automatic leveling of the abrasive media in the respective compartments of the drum.

While there has been here shown and described preferred embodiments of the present invention, it is nevertheless to be understood that various changes may be made therein without departing from the spirit and scope of the appended claim.

What is claimed is:

A barrel for finishing thin metal parts comprising a drum of hexagonal shape in cross section, containing an abrasive media which is movable upon rotation of the drum, the inner walls of opposed sides of the drum being transversely rabbeted at spaced intervals to provide guide- Ways, hexagonal perforated partitions inserted into the guideways of said drum walls and lying in parallelly spaced relationship transversely of the drum, thereby providing compartments in which the thin metal parts are placed, the width of each compartment being less than the width of the thin metal parts being tumbled, to prevent the metal parts turning at right angles to the movement of the abrasive media upon rotation of the drum, said drum being closed on four sides and open on the other two to permit ready insertion and removal of said partitions, to vary the size of the compartments for the accommodation of metal parts of various dimensions, a removable drain and dumping cover complementing and adapted for placement over the two open sides of the drum, said cover being perforated, a removable solid cover adapted for placement over the two open sides of the drum in lieu of said drain and dumping cover during the tumbling cycle, and means for clamping said drain and dumping cover or solid cover in position during rotation of the drum.

References Cited in the file of this patent UNITED STATES PATENTS 1,365,936 Morgan Jan. 18, 1921 1,491,601 Fuller Apr. 22, 1924 1,491,602 Fuller Apr. 22, 1924 1,563,552 Butzbach Dec. 1, 1925 2,785,562 Tigerman Mar. 19, 1959 2,994,165 Brevik Aug. 1, 1961 

